Numerous styles and types of eyeglass and sunglass lens cleaning devices are known. Generally, they fall into three types: (1) mechanical cleaners, (2) cloth cleaners in hard cases, and (3) cleaners made exclusively of soft or pliable materials (hereinafter referred to as "cloth cleaners"). These conventional lens cleaning devices have numerous drawbacks.
Mechanical cleaners tend to be bulky and somewhat complex to use. A bulky item tends not to be carried around. A item that is complicated to use tends not to be used. A further deficiency with mechanical cleaners is that they have moving parts which can fail, thereby reducing reliability. Mechanical cleaners tend also to be hard to wash; lens cleaning devices require frequent cleaning because foreign particles such as dust on the cleaning surfaces can scratch a lens during the cleaning process.
Cloth cleaners in hard cases, such as in U.S. Pat. No. 1,202,774, also tend to be bulky. Bulk is disadvantageous for eyeglass and sunglass cleaners because people like to have these cleaners in their pants or skirt pockets, in their pocketbooks, in their suit pockets and other places with limited space. In clothing pockets, bulky items are uncomfortable. Although the cases help keep the cloth clean (free of dirt, dust and other materials that might scratch or dirty a lens of a pair of glasses), the case is disadvantageous because the cloths must be removed from the case in order to use them. This takes extra effort and time which leads to less frequent use. Cloth cleaners in hard cases also require extra steps to wash the cleaning surfaces.
Finally, simple cloth cleaners generally come in square or rectangular flat pieces that have relatively large surface areas compared to the surface area of a standard eyeglass or sunglass lens. Eyeglass and sunglass lenses are rarely square or rectangular. These cleaners are easily misplaced and hard to find in pockets, bags or pocketbooks. They closely resemble handkerchiefs to the eye and to the touch which increases the danger of foreign particles getting on their surfaces. These cleaners also do not distinguish between surfaces; there is no inside or outside surface. Since these cleaners do not provide defined surfaces, they tend to soil quickly on all their surfaces. A first surface which absorbs oils from the hands on a first cleaning becomes the surface applied to the glasses on subsequent cleanings. Thus, on subsequent cleanings, the oil transferred to the first surface is thereafter transferred to the glass lenses.
Some cloth cleaners come in patterns that resemble somewhat the shape of lenses such as in U.S. Pat. Nos. 399,450; 2,554,630; and 1,091,396. U.S. Pat. 399,450 has a folded shape with a different fabric on each surface. However, that device (and the above-referenced U.S. Pat. No. 1,202,774) has nothing to hold it in its folded shape. Hence there is no readily identifiable inside or outside surface. These devices can lie flat in an unfolded position. The surface that is intended to be the inside, cleaning surface can get dirty just as easily and quickly as the outside surface because nothing prevents the device from unfolding.
U.S Pat. Nos. 2,554,630 and 1,091,396 are devices that are stitched to form pockets; the opening is smaller than the stitched parts which requires a carefully fitting of the lens or lenses into the pocket for cleaning. An undesirable amount of unnecessary time and attention is required to fit the lenses into the pocket. Further, the pocket may not be adaptable to other types of eye wear lenses such as those used for safety goggles. Further, these types of pockets are difficult and costly to manufacturer.